Head structure for gun type oil burners



w. ROBERTS HEAD STRUCTURE FOR GUN TYPE OILBURNIRS Aug. 15, 1950 FiledJune 22, 1946 m m R m .a U a W.

INVENTORL Patented Aug. 1 5, 1950 HEAD STRUCTURE For: GUN TYPE on.

" BURNERS 'W illiain Roberts, Brooklyn, N. Y., assignor to i .Premix.Combustion, Inc., a corporation of New qY rk.

Application "June 22, 1946, Serial No; 678,6? A

" -The obiect'of-this invention is toimprove the 'combustion-efiiciencyof the pressure atomizing orgun-typeoil burner."

Since combustion efiiciency, rapid combustion andhigh flame temperatureare inter-related and dependent on a high-initial temperatureof thecomponents of combustion; there is provided in ideas. (01.158476)practicingfthe inventiona tubular combustion head; whichj'being partlyexposed to heat radi- 'ation from the furnace chamber, preheats air andfuel and produces a highly combustible mixture By accelerating v theflow the burning mixture within the head an by discharging thediffusedfgaseous mixture at such yelocity that, at the e d o t li ei eee m: t n co u tion. ceases and flash combustion occurs at the exit ofthe head the process of mixing is timely and locally separated fromtheprocess of combustionand valuabletime is gained for preheating airand fuel and'for producing, prior to combi sion; a highly combustiblemixture of heated air and oil vapor.

By limiting the duration of internal combustion to the ignition periodand by efliciently transferring the heat absorbed by the head to the;air, the head is maintained at a moderate hightemperature'xand is keptfrom overheating. These means are fully described in the specificationand illustrated in the accompanying drawinginwhichis: I i

. Fig. 1 a front end view of the preheater or combustion head. i

Fig. 2 a section at the line A-'A of Fig. 1 on an enlarged Sscale,showing the preheater in relation to a furnace "wall. J

.Figaa section at the line B.B of Fig. 2.

The preheater or combustion head 'I is shown attached to the dischargebarrel or air tube 2 of an "oil'burner so as to rest by means of aflange whichisshow'n inserted in the front wall 4 of the -W 9r qm u i nhamber a furnace- "The, forwardpart or firing nozzle -5- of thepreheater, extending outsideof'thefuel spray (indicated by dotted lines)and into the combustion chambenis provided with ribs B-and slots '1(Fig. 1). The inner part or air stream heater memher .8 of thepreheater, extending into the discharge barrel in annularly spacedrelation thereto, is provided with annular series of straight ribs orfins 55 disposed on the wall of part 8 in tangential position tothecylindrical bore [0 of the discharge end 5 of the preheater (Fig. 3).Theheat absorbed bypart-B eXtending into the combustion chamber, isconducted to part 8 and transferred by the ribs 9 of large heatinsurface tothe air contacting. the ribs- As the temperature of the airsupplied by the burner 'for. supporting combustion depends on thetemperature, of part 8 and ribs 9, part 3, in order to prevent the lossof. heat to the discharge barrel, is spaced from the discharge barreland the preheater is secured to the oil burner coaxial of the. dischargebarrel by keys or spacers II inserted in slots 1 (Figs- 1, 2) betweenthe .wall of part 8 and the dischargebarrel. t

The air entering spaces orv channels l2 (Fig. 3) between the angularribs-9 is diverted radially by the curved wall section [3 of extension 8(Fig.

. 2) v and passing along ribs 9 enters the central 3 on the rim of thedischarge barrel er airtube,

to the spray-nozzle adapter M and converted into a gas upon dischargeinto the preheated air.

The transfer of heat to air and fuel is greatly increased by placing onfuel line l5 a deflector I6, which, by diverting the air from the centerof the preheater towards the wall of part 8, increases the temperatureof the adapter 14 and causes practically the whole volume of airsupplied by the oil burner to come in contact with heated parts of thepreheater... o

By causing the preheated air to whirl in a plane in angular relation tothe preheater axis and starting the whirling motion at the apex of thefuel spray and by effectively prolonging .it at increased air density inthe contracted discharge end 5 of the preheater a, homogeneous, highlycombustible mixture, of" preheated air and gasified fuel oil is producedwhich mixture, requiring less time for completing chemical union than anordinary, mixture .at room temperature, will burn at greatly improvedefiiciency when discharged into the combustion chamber at increasedvelocity. Because of the large. capacity preheated air and fuel at theconstricted nozzle 5' of the present most desirable or most advantageousarrangement of parts as shown by the drawing, which is drawnsubstantially to scale, facilitates the formation of a highlycombustible mixture within the preheater prior to its discharge into thefurnace chamber.

The electrodes conventionally operate for only two or three minutes andthus cause combustion to begin at the atomizing orifice, and thereafterthe flames advance so as to begin at the forward ,end of the firingnozzle to avoid overheating the ,latter and to afford a longer air andoil intermix-ing path The preheater not located in the path of the flamein the combustion chamber but partly exposed to the heat of combustionis maintained at latemperature not affecting its material by theeflicient transfer of heat to the air passing through the preheater.

With the object of achieving smokeless combustion the present-day oilburner is generally operated with a high percentage of excess air at theexpense of efficiency.

This invention by simple means improves combustion, causes the flame tochange its, colour from red to white, facilitates smokeless combustionatreduced air supply, and reduces fuel consumption and eliminates theformation of carbon in furnace and stack.

The invention includes a method of vaporizing and burning oil bypreheating oil and air and imparting heat to an atomized freelyexpanding stream of oil while intermixing the same with a whirling massof air, to produce a gaseous combustible mixture in a small compactspace which "derives its heat directly from the combustion chamberitself. It will be understood that the annular wall I3 may produce awhirling but in lesser degree than the ribs 9,

I claim:

l, in a gun type oil burner having an air tube and an oil spray nozzlepositioned wholly within said air tube, said spray nozzle being spacedfrom a free discharge end of said air tube, a tubular i;

combustion head for fitting to said discharge end I comprising an airstream heater member adapted to extend coaxially within said air tub-espaced radially therefrom and to surround the oil spray nozzle whenfitted to said tube, a firing nozzle terminating said heater member andextending beyond said air tube discharge end, and means carried by saidcombustion head securing the latter to said air tube with the heatermember extending in radially spaced position, said firing nozzle beingformed with a bore of reduced cross sectional area with respect to thatof said heater member for increasing the velocity of flow of a mixtureof oil and air from the oil spray nozzle and the air tube, said heatermember being formed with internal longitudinally extending ribs intangential relation to an imaginary extension of the inner surface ofsaid bore of the firing nozzle and terminating at the inner rim of saidfiring nozzle for preheating the air, said 4 ribs being so constructedand arranged with respect to the walls of said heater member as todeliver the preheated air in a whirling motion into atomized oil fromthe oil spray nozzle within region of said heater member adjacent saidinner rim of said firing nozzle.

2. A tubular combustion head for oil burners, comprising an air streamheater portion, and a firing nozzle portion extending forwardly from andcoaxially and integrally formed with said heater portion, said firingnozzle having a bore of reduced cross sectional area with respect tothat of said heater portion, the latter being formed with internal finslongitudinally extending in tangential relation to an imaginaryextension of the inner surface of the bore of the firing nozzle andterminating at the inner rim of said firing nozzle.

3'. An apparatus of the character described comprising an air tube of agun type oil burner having a discharge end, a nozzle for spraying oil ina cone positioned within said tube spaced inwardly from said end, acombustion head coaxially fitted into said discharge end in radiallyspaced relation thereto and adapted to extend into a furnace chamber toreceive heat radiation therefrom, said head including an air streamheater member extending within said air tube in radially spacedrelation, said heater member being terminated by a firing nozzleextending beyond said air tube discharge end, said firing nozzle havinga substantially cylindrical bore reduced in cross-sectional area withrespect to that of said heater'member for increasing the velocity offlow of discharge from the oil spray nozzle and air heater member priorto entering the furnace chamber, said heater member being formed withinternal fins longitudinally extending in a tangential relation withrespect to an imaginary extension of the inner surface of said firingnozzle bore, said heater member having a curved inner surface graduallydecreasing in cross-sectional area joining the bore of the firingnozzle, said fins terminating at sai'd' curv'ed inner surface, forpreheating the air stream and for delivering the latter in a whirlingmotion at right angles to the combustion head longitudinal axis into anapex region of the oil spray cone, and means for securing saidcombustion head to said air tube discharge end in said spaced relation.

4. An apparatus of the character described comprising an air tube of agun type oil burner having a discharge end and a nozzle for spraying oilin a cone positioned within said tube spaced from said end, a combustionhead coaxially fitted into said discharge end and adapted to extend intoa furnace chamber to receive heat radiation therefrom, said headincluding an air stream heater member extending within said air tube inradially spaced relation terminated by a firing nozzle extending beyondsaid air tube discharge end, said firing nozzle having a bore reduced incross sectional area with respect to that of said heater member forincreasing the velocity of flow of a mixture from said oil spray nozzleand air heater, internal finsextending longitudinally the heater memberin tangential relation to an imaginary extensionof the inner surface ofthe bore of the firing nozzle and terminating at the inner rim of saidfiring nozzle for reheating the air and for delivering the pre heatedair in a whirling motion, into the apex region of the oil spray cone.

WILLIAM ROBERTS,

(References on following page) REFERENCES CITED The following referencesare of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,953,483 Higinbotham Apr. 3,1934 1,990,088 Noe Feb. 5, 1935 2,065,042 Berryman Dec. 22, 1936 Number6 Name Date Good Jan. 12, 1937 Powers et a1. June 14, 1138 Mueller eta1. Oct. 29, 1940 Jones Nov. 12, 1940 Hammer Nov. 19, 1940 Mueller Apr.29, 1941 Roberts Oct. 31, 1944

